feat(#92): unify search, filter, and command palette in the header

[sarg3nt]

Summary

• New global HeaderSearch input drives search, per-gear filter, and the Cmd/Ctrl+K command palette from a single text field at the top of every page. Header is now full-width above the sidebar so the input is visually viewport-centered. Leading > enters palette mode (slide-down panel under the input, no centered modal); backspace over > exits. / focuses, Esc clears/blurs.
• Per-gear filter inputs are removed across the codebase. Each gear's page script now registers via window.gearbox.filter.register({onInput,onSubmit,onClear}); toolbar buttons + dropdowns also surface as palette commands via window.gearbox.commands.register({id,label,group,run}). Logs alone registers 27 commands (16 dynamic log sources, 4 line counts, 3 severities, refresh/copy/download/fullscreen).
• Help overlay (?) redesigned as full-window smoked glass — no panel, no border, shortcuts laid out in a centered two-column grid directly on the blurred backdrop, per the issue spec.

Closes #92

Test plan

• HAProxy: / focuses search; typing "bazar" filters backend cards down to one.
• Home: typing fades non-matching tiles; Enter opens first match; empty-input Enter falls back to a DuckDuckGo search in a new tab.
• Logs: Cmd+K → > prefix appears, palette opens; "log s…" + ↵ switches the log source; "100" / "200" / etc. set line count; "copy", "download", "fullscreen" all work via the palette.
• Alerts / Services / OS Updates / Bx / Traffic / Metrics / Certificates: each gear's filter (where present) drives via the HeaderSearch; each gear's toolbar surfaces commands in the palette.
• Help overlay: ? opens full-window smoked glass; Esc, backdrop click, or ? again closes. Shortcuts render in a centered 2-column grid with no panel chrome.
• Box width stable across idle ↔ typing ↔ palette mode at lg+ (no visible width shift on keystroke).
• Responsive: hint chips drop out below lg (~1023px) and the box shrinks; row collapses to a magnifying-glass button below md (~767px).
• Narrow desktop (~1280px): right-side toolbar fully visible; left chip/breadcrumb truncates; search shifts left to give the right column priority.
• Wide desktop (≥ 2400px): search visually centered on viewport (≤4px off at 3000px).
• Palette panel never collapses to an unusable strip on narrow viewports — minimum width 360px, clamped within the viewport with an 8px gutter.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR implements issue #92 by introducing a unified HeaderSearch input in the global header that drives (1) per-gear filtering, (2) global DuckDuckGo fallback search, and (3) a redesigned command palette that appears as a slide-down panel anchored to the header input. It also updates multiple gears to register filter + command palette entries via new window.gearbox registries, and redesigns the ? shortcut overlay to a full-window smoked-glass layout.

Changes:

• Add global HeaderSearch controller and per-page window.gearbox.{filter,commands} registries; remove scattered per-gear filter inputs.
• Redesign command palette to reuse the header input (palette mode via leading >), including per-gear commands registration.
• Redesign shortcut help overlay (?) to a full-window smoked-glass reference grid and keep universal Esc handling.

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
gearbox/static/js/common/header-search.js	New unified header search controller: / focus, Cmd/Ctrl+K palette mode, dispatch to registered filter callbacks, mobile compact behavior.
gearbox/static/js/common/gear-commands.js	New page-scoped registries for per-gear filter handlers and command palette commands (window.gearbox).
gearbox/static/js/common/command-palette.js	Command palette redesigned to be a slide-down panel driven by HeaderSearch query and per-gear commands.
gearbox/static/js/common/shortcut-help.js	Shortcut help overlay redesigned; continues to own universal Esc behavior.
gearbox/internal/framework/templates/layouts/base.templ	Header layout reworked to full-width above sidebar; adds HeaderSearch + slide-down panel markup; script load order updated.
gearbox/static/js/gears/home.js	Home tile filtering and “open first match / DDG fallback” now wired through HeaderSearch filter registration; adds palette commands.
gearbox/internal/gears/home/pages.templ	Removes the Home-local search form; documents new HeaderSearch usage for Home.
gearbox/internal/gears/bx/pages.templ	Removes visible Bx search input; keeps hidden input for Tabulator search binding.
gearbox/static/js/bx/bx-page.js	Registers Bx filter proxying into hidden #bx-search; registers palette commands for view + add box.
gearbox/internal/framework/templates/pages/os_updates.templ	Removes visible package search input; keeps hidden input for Tabulator binding.
gearbox/static/js/os-updates/os-updates-page.js	Registers OS Updates filter proxying into hidden #pkg-search; registers palette commands.
gearbox/internal/framework/templates/pages/services.templ	Removes page-local services text filter; replaces with HeaderSearch-driven query variable + palette commands.
gearbox/internal/framework/templates/pages/overview.templ	Removes HAProxy overview text filter input; uses HeaderSearch-driven query variable + palette commands; restores saved query.
gearbox/internal/framework/templates/pages/logs.templ	Removes Logs page-local text filter input; uses HeaderSearch-driven query variable; registers extensive Logs palette commands.
gearbox/internal/framework/templates/pages/metrics.templ	Adds palette commands (edit toggle, refresh).
gearbox/internal/framework/templates/pages/certificates.templ	Adds palette command (refresh).
gearbox/internal/framework/templates/pages/alerts.templ	Removes visible alert search input; wires filter + palette commands via registrations.
gearbox/static/js/traffic/traffic-visualization.js	Adds palette commands for view dropdown + actions (reset/physics/refresh).

Comments suppressed due to low confidence (2)

gearbox/static/js/common/header-search.js:349

• In compact/mobile mode, this outside-click handler will never collapse the expanded search row because #header-search-row always retains the hidden class (CSS overrides display via .header-search-expanded). As written, row.classList.contains('hidden') stays true even when the row is visible, so clicks outside won’t call collapseCompact().

Consider checking for row.classList.contains('header-search-expanded') instead (or removing/adding hidden in JS when expanding/collapsing).

        // Compact-mode: clicking outside the search collapses the row.
        document.addEventListener('click', function (e) {
            if (!window.matchMedia('(max-width: 767px)').matches) return;
            if (!row || row.classList.contains('hidden')) return;
            if (wrap && wrap.contains(e.target)) return;
            // Don't collapse while the palette panel is the click target.
            const panel = document.getElementById('header-search-panel');
            if (panel && panel.contains(e.target)) return;
            collapseCompact();

gearbox/internal/framework/templates/layouts/base.templ:2481

• The HeaderSearch behavior documentation here says the placeholder switches to the page-provided window.gearbox.filter.register({ placeholder }), but header-search.js currently ignores the placeholder and keeps a single shared placeholder/hint UI. This mismatch will confuse future changes.

Either update the comment to reflect the current behavior, or wire the registered placeholder into the input (and ensure it doesn’t cause layout shift).

// HeaderSearch is the unified search / filter / command-palette input.
// One text input drives three behaviours, chosen by what the user types:
//   - empty / search mode: hint reads "Type / to search · Cmd+K for palette".
//     Per-gear pages can register a filter callback via window.gearbox.filter
//     (see common/gear-commands.js); when active, the placeholder switches
//     to whatever the page asked for and each keystroke calls the callback.
//     With no filter callback registered, Enter falls back to a DuckDuckGo
//     web search.